The quickest solution is to find where the leak occurs. You will need a bucket, sink, or bath tub to submerge just the cylinder, and the hose. Do not submerge the trigger pump. Seal the cylinder against your body, no need to fill up with water. Submerge the cylinder and the hose. If you use the water trap, submerge that too. Slow, and I mean very slowly, pump. Where there is a leak, you will see heading of ponding water. Once you discover where it is, we can assist with the patching or work around.
If you have left the trigger pump in a hot environment for a while, it may cause a seal to warp. Same for if you have water intruded into the pump, it can cause the seal to warp.
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